BACK PAIN

Thoracic & Lumbar Spine

Last updated – Feb 20122

Session Aims

Define acute, subacute& chronic presentation Focus on assessment of common problem Learn risk assessment for serious causes Nonspecific back pain in detail Detail on not to miss diagnosis

Last updated – Feb 20123

introduction

Very common problem: second after URTI to primary health Commonest work-related disability <45

Only about 5% have a serious cause Need to ID serious cause & avoid over Ix and

‘medicalising’ nonspecific Easiest to use a system of identifying risk

factors, mainly Hx, some Exam Rarely needs Ix, need to know who

Last updated – Feb 20124

DEFINITIONS

Acute = <6/52 80-90% resolve

Subacute = 6-12/52 Chronic = >12/52

Last updated – Feb 20125

NOT TO MISS DIAGNOSES

VASCULAR AAA, Thoracic Aortic Dissection

Infection Epidural abscess, osteomyelitis, discitis

Osteoporotic crush # Malignancy Compression syndromes Cord, cauda equina, conus medullaris

Last updated – Feb 20126

CAUSES - SPINE

Musculoskeletal – m.spasm, ligament Disc - >90% L4-5/L5-S1 Osteoporotic crush # Malignancy

Last updated – Feb 20127

CAUSES - INFECTIOUS

Osteomyelitis – bacterial, TB Epidural abscess Discitis

Last updated – Feb 20128

CAUSES-NON SPINE

Vascular – dissection, leaking aneurysm, AMI Pancreatitis PE Renal – PNR, colic (Non-organic)

Last updated – Feb 20129

General risk factors - HISTORY

Pain >6/52 Age<18, >50 (tumour, infection) Minor trauma in elderly (crush #’s) Fever, rigours Weight loss (tumour, infection) IVDU Immucompromise Nocturnal pain, pain at rest Incontinence Saddle anaesthesia Past Hx cancer

Last updated – Feb 201210

General risk factors - EXAM

Fever, writhing in pain (infection) Anal sphincter laxity (compression) Perineal Sensory loss Major motor weakness (nerve root or cord

compression) Positive SLR (disc herniation)

Last updated – Feb 201211

RISK ASSESSMENT

Aortic dissection, rupturing AAA, spinal epidural abscess and PE most commonly don’t present in a classical way

The best way to make these diagnoses is by specifically considering them and looking for risk factors

Last updated – Feb 201212

EXAMINATION

Vital signs are important! Examine the abdomen The back itself Neurological examination Straight leg raise Consider PR examination

Last updated – Feb 201213

Examination of the back For evidence of infection (skin etc.) Point tenderness for infection and fractures sens 86%, spec 60%

Range of motion not helpful

Last updated – Feb 201214

Lower limb neuro exam

NERVEROOT

L4 L5 S1

MOTOR QUADRICEPS DORSIFLEXIONGREAT TOE& FOOT

PLANTAR FLEXIONGREAT TOE&FOOT

SCREENINGTEST

RISE FROM SQUAT

HEEL WALKING TOE WALKING

REFLEX KNEE - ANKLE

Last updated – Feb 201215

dermatomes

For L4 test anterior lower thigh

L5 test lateral calf S1 posterior calf

and lateral foot

Last updated – Feb 201216

Distribution of pain

Last updated – Feb 201217

Determining level of cord compression

Establish a sensory level

Last updated – Feb 201218

Straight Leg Raise

Lie pt. down, passive leg raise, knee extended

Stop when patient says to, note where pain is Dorsiflex ankle at this point True positive is: Sciatic or radicular pain below knee Not back pain or buttock pain pain elicited before hamstrings move pelvis

Specific not sensitive for disc prolapse

Last updated – Feb 201219

PR examination – who gets one?

Anyone with faecal retention, incontinence, saddle anaesthesia

Consider in anyone with severe pain Any neurological defecit Looking for: Mass (prostate, rectal) and rule out abscess Rectal tone and saddle sensation (compression)

Last updated – Feb 201220

‘Nasty’ diagnoses reminder

VASCULAR AAA, Thoracic Aortic Dissection

Infection Epidural abscess, osteomyelitis, discitis

Osteoporotic crush # Malignancy Compression syndromes Cord, cauda equina, conus medullaris

Last updated – Feb 201221

Thoracic Aortic Dissection

Classic Hx: sudden onset, tearing chest pain, radiates

interscapular less than 1/3

Examination: HTN (1/3 normal BP), BP dif. Arms >20 (?25%, often in normal people) new diastolic murmur (sens. 28%)

Most signs AFTER the catastrophe!

Last updated – Feb 201222

Ruptured AAA

Classic triad: Abdo pain, low BP, pulsatile mass <20% of patients

can be LLQ pain, flank pain, isolated back pain

Leads to misdiagnosis: as diverticulitis, PNR, colic, musculoskeletal leads to mortality of 75%

abdo mass palpation sensitivity may be 45%

Last updated – Feb 201223

Aortic catastrophe risk factors

Usual vascular RF’s: Male, old age, HTN, Smoking

Aortic abnormalities: Connective tissue disease, chromosomal

abnormalities, inflammatory aortic conditions, bicuspid aortic valve, aortic instrumentation

PREGNANCY Illicit drug use – esp. cocaine,

?amphetamines

Last updated – Feb 201224

pitfall Aortic catastrophes (dissection and AAA) can

present with neurological symptoms In 18-36% pt.s with dissection! Acute stroke Unilateral leg weakness (radicular artery)

About 5% AAA rupture pt.s Haematoma around AAA pressure on femoral n. can cause weak hip and knee flexion

Last updated – Feb 201225

Aortic imaging guidelines AAA exclusion needs to done in any elderly patient

with new onset severe back pain Ultrasound can be used to determine size of aorta

(ED ultrasound widely used for this) Doesn’t determine leak or rupture Normal size aorta won’t do this

Age greater than 55 and severe back pain? Use CT to diagnose renal colic or diverticulitis

Last updated – Feb 201226

EPIDURAL ABSCESS

classic triad:– fever, back pain, neurological defecit

occurs only 13% 75% afebrile, 2/3 normal initial neurological exam Risk factor Ax best chance ID before neuroprob

Last updated – Feb 201227

Epidural abscess risk factors

Recent epidural/spinal anaesthetic** Generally related to immunocompromise Normal immune reaction leads to symptoms!

Diabetes Alcoholism Chronic renal failure Steroid use HIV/AIDS IVDU

Last updated – Feb 201228

Staph most common isolated organism About 1/3 gram negative Requires prompt antibiotic treatment GN requires 3rd generation cephalosporin GP requires Blactamase stable penicillin

and consider vancomycin if ?MRSA Needs urgent Confirmation of diagnosis – MRI now surgical consultation: May do biopsy to isolate organism B4 AB’s

Last updated – Feb 201229

Spinal metastases

Risk factor is malignancy of any type Commonest are prostate, breast, lung Also MM, lymphoma, RCC, bowel

Need to think about cord compression

Last updated – Feb 201230

PE

Can present as back pain Should also do a risk factor assessment for

thromboembolism This is a talk for another day!

Last updated – Feb 201231

INVESTIGATION - bloods

Looking for infection FBE can be normal, but… ESR always elevated, ?CRP too

Last updated – Feb 201232

IMAGING - Xray

Very few indications according to some for Xrays to investigate non-traumatic back pain

Possible indications: For suspected fracture, tumour, infection Can’t be relied on to exclude: Sensitivity spine met.s only 60%, 17% cord

compression Xray normal, 2/3 osteomyelitis normal first 7-10/7

Oblique views are NOT necessary Extra radiation and insenstive

Last updated – Feb 201233

CT

Sensitive for spinal metastases, fractures Can identify disc prolapse, but Inferior to MRI Doesn’t show cord or spinal canal well

Last updated – Feb 201234

MRI

Only investigation able to exclude compression syndromes

For suspected infection For soft tissue tissue tumours

Last updated – Feb 201235

Disc Prolapse most important issue is motor radiculopathy

only 2-3% of acute lower back pain have this need prompt referral, urgent MRI & surgeon r/v

within a week probably reasonable 95% are at L4/L5 or L5/S1

Neurology at lower level eg. L4/L5 causes L5 lesion Acute surgical indications for motor symptoms Isolated sensory problems generally not a problem

Last updated – Feb 201236

NONSPECIFIC BACK PAIN

Preferred terminology to ‘sprain/strain, mechanical, lumbago’ (most people never get more specific diagnosis,

no histopath ‘strain’) Usu. mild to moderate pain exacerbated by movement, relieved with rest often minor exertion, lifting, may not be any

clear etiology

Last updated – Feb 201237

Management - EXPLANATION

Explain reason for lack of imaging: Pathology not important

Reason for not admission: normal activities better than exercise or bed rest

What to do and not to do leg lifting not back in and out of bed not heat & massage for 24H

Explanation re use of pain killers Likely time course and GP follow up

Last updated – Feb 201238

Mx - analgesia

Paracetamol first line, regular NSAID’s not significantly better, more SE’s Avoid ketorolac in: elderly, risk renal failure, peptic ulcer disease

Opiates for: moderate to severe pain, short term, GP consultation

‘muscle relaxants’ eg diazepam: controversial not better than NSAID’s, no added benefit

Last updated – Feb 201239

Opiates and permits It is a requirement of Department of Human Services, Health Insurance

Commission, and Medical Practitioners Board of Victoria that any opiate prescription beyond short term requires permit with ONE medical practitioner.

Illegal and unprofessional to prescribe purely to maintain dependence or avoid withdrawel. Unprofessional to label someone a drug addict and leave them in pain. In the ED best to refer to the senior doctor on duty In the ED best to have a culture/policy of no repeat scripts regardless of the excuses

for missing medication Showing compassion and limited amount to allow patient to see their GP next working

day is professional The GP has a duty of care to see that patient urgently and take them out of the doctor

shopping loop. Appropriate documentation of management plan, including timeframe to cease

opiates, referral to appropriate specialist Appropriate confirmation of identity Doctor shopping hotlines Active market to sell these drugs.